/* Shared site layer: fonts, tokens, header/footer, buttons, focus, motion.
 * Loaded by every page. Pages that also load style.css load this file after it. */

@font-face {
  font-family: "Fraunces";
  src: url("assets/fonts/fraunces-latin-400-normal.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Fraunces";
  src: url("assets/fonts/fraunces-latin-400-italic.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: "Fraunces";
  src: url("assets/fonts/fraunces-latin-600-normal.woff2") format("woff2");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Fraunces";
  src: url("assets/fonts/fraunces-latin-600-italic.woff2") format("woff2");
  font-weight: 600;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: "Inter";
  src: url("assets/fonts/inter-latin-400-normal.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Inter";
  src: url("assets/fonts/inter-latin-600-normal.woff2") format("woff2");
  font-weight: 600 800;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "JetBrains Mono";
  src: url("assets/fonts/jetbrains-mono-latin-500-normal.woff2") format("woff2");
  font-weight: 400 600;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: dark;

  /* Surfaces: a darkroom, not a dashboard. */
  --ink-0: #0a0d12;
  --ink-1: #0f141c;
  --ink-2: #151b26;
  --ink-3: #1c2431;
  --hairline: rgba(214, 226, 244, 0.12);
  --hairline-strong: rgba(214, 226, 244, 0.22);

  --text-1: #eef2f8;
  --text-2: #bcc6d6;
  --text-3: #8f9bb0;

  /* Human register: film light. Science register: the evidence trio. */
  --warm: #f2b872;
  --warm-soft: rgba(242, 184, 114, 0.14);
  --warm-strong: #ffd3a1;
  --known: #79f2c9;
  --plausible: #8fb4ff;
  --speculative: #ff9ec4;

  --font-serif: "Fraunces", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --font-sans: "Inter", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --radius-s: 8px;
  --radius-m: 14px;
  --radius-l: 22px;
  --page-max: 1160px;
  --gutter: clamp(16px, 4vw, 40px);
  --header-h: 60px;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body.site {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  background: var(--ink-0);
  color: var(--text-1);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Film grain: one static texture, no animation cost. */
body.site::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

:where(.site) a {
  color: inherit;
}

.site :focus-visible {
  outline: 2px solid var(--warm);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  top: -48px;
  left: 16px;
  z-index: 100;
  padding: 10px 14px;
  border-radius: var(--radius-s);
  background: var(--warm);
  color: #1b1206;
  font-weight: 600;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 12px;
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--hairline);
  background: rgba(10, 13, 18, 0.78);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
}

.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: min(var(--page-max), 100% - 2 * var(--gutter));
  height: var(--header-h);
  margin: 0 auto;
}

.wordmark {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  min-width: 0;
  color: var(--text-1);
  text-decoration: none;
  white-space: nowrap;
}

.wordmark strong {
  font-family: var(--font-serif);
  font-size: 1.22rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.wordmark span {
  color: var(--text-3);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  padding: 8px 12px;
  border-radius: 999px;
  color: var(--text-2);
  font-size: 0.9rem;
  text-decoration: none;
  transition: color 0.2s ease, background 0.2s ease;
}

.site-nav a:hover,
.site-nav a[aria-current="page"],
.site-nav a.is-active {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-1);
}

.menu-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--hairline-strong);
  border-radius: 999px;
  background: transparent;
  color: var(--text-1);
  font: 600 0.85rem var(--font-sans);
  cursor: pointer;
}

.menu-toggle-bars {
  position: relative;
  width: 14px;
  height: 10px;
}

.menu-toggle-bars::before,
.menu-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.2s ease, top 0.2s ease;
}

.menu-toggle-bars::before { top: 1px; }
.menu-toggle-bars::after { top: 7px; }

.menu-toggle[aria-expanded="true"] .menu-toggle-bars::before { top: 4px; transform: rotate(45deg); }
.menu-toggle[aria-expanded="true"] .menu-toggle-bars::after { top: 4px; transform: rotate(-45deg); }

.nav-comments {
  margin-left: 6px;
  padding: 7px 12px;
  border: 1px dashed rgba(242, 184, 114, 0.5);
  border-radius: 999px;
  background: transparent;
  color: var(--warm-strong);
  font: 600 0.82rem var(--font-sans);
  cursor: pointer;
}

.nav-comments[hidden] {
  display: none;
}

/* ---------- Shared bits ---------- */

.byline-link {
  color: var(--warm-strong);
  text-decoration: underline;
  text-decoration-color: rgba(242, 184, 114, 0.45);
  text-underline-offset: 3px;
}

.byline-link:hover {
  text-decoration-color: var(--warm);
}


.eyebrow-mono {
  margin: 0 0 14px;
  color: var(--warm);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 11px 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  font: 600 0.95rem/1.2 var(--font-sans);
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.2s var(--ease-out), background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--warm);
  color: #1d1307;
}

.btn-primary:hover {
  background: var(--warm-strong);
}

.btn-ghost {
  border-color: var(--hairline-strong);
  background: rgba(255, 255, 255, 0.02);
  color: var(--text-1);
}

.btn-ghost:hover {
  border-color: rgba(242, 184, 114, 0.6);
}

.arrow {
  display: inline-block;
  transition: transform 0.2s var(--ease-out);
}

a:hover > .arrow,
.btn:hover .arrow {
  transform: translateX(3px);
}

.tier-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid var(--hairline-strong);
  border-radius: 999px;
  color: var(--text-2);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-decoration: none;
}

.tier-chip i {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--known);
  box-shadow: 0 0 10px var(--known);
}

/* ---------- Page scaffolding shared by the new-style pages ---------- */

.page-main {
  width: min(var(--page-max), 100% - 2 * var(--gutter));
  margin: 0 auto;
}

.page-main :is(h1, h2, h3, h4) {
  font-family: var(--font-serif);
  font-weight: 400;
  letter-spacing: -0.015em;
}

.page-main em {
  font-style: italic;
}

.section {
  padding-block: clamp(56px, 9vw, 112px) 0;
}

.section-head {
  max-width: 760px;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.section-head h2,
.h3-lg {
  margin: 0;
  font-size: clamp(1.9rem, 4.2vw, 3rem);
  line-height: 1.08;
}

.section-head h2 em,
.h3-lg em {
  color: var(--warm);
}

.section-dek {
  margin: 16px 0 0;
  color: var(--text-2);
  font-size: clamp(1.02rem, 1.6vw, 1.14rem);
  line-height: 1.65;
}

.step-label {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 14px;
  color: var(--text-3);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.step-label span {
  display: inline-grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border: 1px solid rgba(242, 184, 114, 0.5);
  border-radius: 50%;
  color: var(--warm);
  letter-spacing: 0;
}

.dot {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
}

.dot.known { background: var(--known); box-shadow: 0 0 10px rgba(121, 242, 201, 0.6); }
.dot.plausible { background: var(--plausible); box-shadow: 0 0 10px rgba(143, 180, 255, 0.6); }
.dot.speculative { background: var(--speculative); box-shadow: 0 0 10px rgba(255, 158, 196, 0.6); }

/* ---------- Reveal on scroll ----------
 * Pure CSS scroll-driven animation: browsers without support simply show the
 * content, and nothing depends on JavaScript to become visible. */

@keyframes reveal-up {
  from { opacity: 0; transform: translateY(26px); }
  to { opacity: 1; transform: none; }
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .reveal {
      animation: reveal-up linear both;
      animation-timeline: view();
      animation-range: entry 0% entry 55%;
    }
  }
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--hairline);
  margin-top: 40px;
}

.site-footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  width: min(var(--page-max), 100% - 2 * var(--gutter));
  margin: 0 auto;
  padding: 26px 0 34px;
  color: var(--text-3);
  font-size: 0.86rem;
}

.site-footer a {
  color: var(--text-2);
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--text-1);
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}

/* ---------- Tablets and phones ---------- */

@media (max-width: 980px) {
  .menu-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: calc(var(--header-h) - 1px);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 10px var(--gutter) 16px;
    border-bottom: 1px solid var(--hairline);
    background: var(--ink-0);
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.55);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    padding: 12px 10px;
    border-radius: var(--radius-s);
    font-size: 1rem;
  }

  .nav-comments {
    align-self: flex-start;
    margin: 6px 0 0;
  }
}

@media (max-width: 640px) {
  .wordmark strong {
    font-size: 1.02rem;
  }

  .wordmark span {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}